Hello and welcome to this Solid Round Tools knowledge session. During this series we will cover features, strategies and products relating to Solid Round Tools. As always we start with safety. Safety is our top priority at Sandvik Coromant. Please ensure you are watching this in a safe environment. Beware of the safety procedures, exits and assembly points at the building which you are viewing. My name is Ben Lodge and I'm the Solid Round Tools product specialist for Sales Area North Europe and today I'm joined by Martin Saunders. Hello yes I'm Martin and I am the Grade Development Specialist for Sales Area North Europe. So today we're going to be looking into aerospace, aerospace applications and one of the considerations Martin when we're looking at aerospace is looking at the materials. So you're going to tell us a little bit about the dynamics of the materials that we see within the aerospace industry. Yeah sure. Okay yes so today we're going to be talking about titanium and nickel based alloys. And there are a few areas when we look at these materials that we have to think about before we start to think about machining strategies. And the most important is thermal conductivity. Now we know with materials such as titanium they have very poor levels of thermal conductivity. So we can see from the diagram to the side of us that when you look at titanium it sits in one of the areas where metals have the lowest thermal conductivity. Okay. So it creates problems when you start to machining because you cannot get the heat away from the cutting area quickly enough. Now another area we need to sort of think about is the area of thermal expansion. Now the reasons people use titanium are when you have two components with very tight tolerances. They don't expand and contract so much with heat. Right. So therefore it's a very preferable property to have in these materials. Unfortunately that causes other problems when we come to machinability. So I suppose that gives us quite a lot of challenges that we have to kind of look at and investigate because there's only one place that that heat can go and that's in the tool I suppose when we're machining. Absolutely. So if we look at titanium alloys to start with we can say that we can broadly split titanium into two different areas. So you've got the beta alloys and you've got the alpha alloys. Okay. So you've got a transition point a temperature at around 890 degrees where the material moves from a hexagonal close packed structure into a body centered cubic structure. Now whilst that may not mean a lot at the moment as we go into the properties of the materials you'll see why they're so important. Now what we can do we can add different alloying elements to the material so we can stabilize that material at certain temperatures. So we can actually then create the properties we want in material by changing the alloying elements. Okay. So what we see with the two different alloys we've got the alpha alloys we've got the beta alloys. But when you look at the alpha crystal structure you can see that you have a much lower density, you have a lower strength, but you have a higher creep resistance. So you can see there are properties in there that are desirable in a material. You have improved machine ability. The alpha alloys are much easier to machine than the beta alloys. But you also have poor resistance to stress corrosion cracking, which is something you don't really want. So when we add alloying elements we can actually create a beta structure. Okay. Okay. So then we can get a higher density, we can get a higher strength, but we can also greatly increase the resistance to the stress corrosion cracking. So you see this type of material in things like aircraft landing gear. Right. Okay. And that's a big area where they need that, where you get that constant stress on the material. Yeah. So you've got properties that are desirable for both areas depending on what you want to do with the finished component. But of course, when we look at things like this, we then start thinking of machine ability. Yeah, absolutely. I suppose there's going to be a big difference between the two then because we've got that different in the structure of them. Of course. Yeah. Now the common materials we see are the alpha beta alloys, so the 6-4, Stalium 6-4. It's a common material we see everywhere. So if we give a machine ability factor rating of one, we can then work around the other areas and we can actually decide, okay, so we need to either increase or decrease our cutting speed, our feeds, our depth of cuts, depending on the amount of alloying elements in that material. Okay. So if you look at the alpha alloys, they're much easier to machine. So you've got machine ability factors there of 1.1, 1.2, 1.6. So a lot faster speeds, cutting speeds. But when we look at the beta alloys, so the body centered cubic structure, we've then got to start thinking, oh, we've got more difficult machine materials here. So we've got to then start reducing the cutting data. And then this chart is a very good chart we can use that shows us the machinability factor of each material. Okay. But of course, when we start to look at the materials, you then start to think, well, how does this translate into the cutting characteristics? Yeah. So we have challenges when we come to machine these materials. When we look at materials that have high strengths, that is retained when we've got the high temperatures, then we start to think, okay, what's this going to do? What's this going to do to the cutting edge? And of course, we're going to create a lot of heat at that cutting edge. And that is going to be a big problem for us. We've got a very narrow contact area. So when you look at the way that the swarf breaks and the contact to the material, it's much less than you get with steel. So therefore, you get high stresses. Right. You get very high stresses right at the cutting edge. Obviously, it's titanium. And our coatings are titanium carbon nitrides. Right, okay. So you get this chemical reaction between the material and the tool, especially at high temperatures. And what this causes is adhesion, smearing. So you've got material sticking to the work tool. Okay. And of course, as soon as that tool, the material starts to stick, breaks off, cracks the edge line, you start to lose the cutting edge. Yeah. Yeah. Then we look at the chip formation. With titanium, it's a cyclic chip formation. So you've got the constant changes all of the time of the cutting forces. So you've got the changes in the cutting force, which cause then vibration, chatter, other things like that. So these are all things you have to think about when you're starting to plan, plan the cutting process. Because we have a low modulus of elasticity, we then start to have problems with vibration, chatter, because the material is starting to move around a little bit. And we need to be careful of that. So when we combine all that together, you can see that we have a combination of mechanical, thermal and chemical wear. Now, all these different actions acting on the cutting edge. So then we're going to end up with a lot of edge chipping. We're going to end up with thermal cracks. We're going to end up with notch wear. So these are the common wear patterns we're going to see. So I suppose that it's really important to have that balance then between selecting the correct grade and having the correct geometry as well to kind of counteract all these different challenges, shall we say. Yeah, exactly, exactly. When we start to look at this, we can see that the wear patterns we get are mostly notch wear, thermal cracks and edge line chipping. And it's all down to the poor thermal conductivity of this material. Okay. And we've got to really start to think about what grades we're going to use and what geometries we're going to use. What we shouldn't forget is a lot depends on the machine itself. We've got to have rigid tooling and fixturing and machines. And we have to have a control on the machine that can cope with very rapid changes of direction. So there's a lot of things you'd think of outside of the cutting tool. I suppose that these kind of differences in the machine or the fixture or the tooling can really impact the tool life thing because, you know, it could kind of kind of multiply the issues that we're having if we've got instability already there. Yeah. Yeah. Yeah. Yeah. So if we can eliminate those issues first before we then start to look at the cutting strategies. One thing that we should all be aware of is that titanium can cause, does have a risk of fire. Because you've got oxidized surfaces constantly from the chips, there's always a risk that as soon as that material leaves the cutting edge, it could cause a fire. Right. Okay. So we should be aware that we use coolant and we clean the machine properly. It's just that it's just general housekeeping that we should do to ensure that we don't have a problem. Okay. Yeah. So, it's rare, but it can and it does happen. So when it comes to being successful when you're machining these products, it's always, when we say, how should we cut this with a milling cutter? We should always use Klein Milling. That's important. We should always go from a thick to a thin chip. Yeah. Because we don't want to create any end due force on that cutting tool. Of course, chip thinning is important. Yeah. You know from experience. Absolutely. I mean, that's what the high feed side milling strategy is based on. And I know we'll talk a little bit more about that, but we see that as an important factor within this machining area. Yeah. Coolant is a must. Always use coolant. It's all about controlling the heat. If we can control the heat, then we can create a cutting process that is stable and productive. Now, that's the most important thing. And of course, yes, always use the shortest tool possible, but we know sometimes that isn't possible. So it's very much about adapting a strategy to suit the components. Absolutely. And the strategy is important when we, when we come to this type of, type of components. So within this area, we've talked about the machine. We've talked about the material. So now obviously we're going to have a little look about the grades as well. And it's important to have kind of a, the correct grade kind of structure makeup between, you know, what we're using when we're machining, not only in solid round tools, but in all the areas that we machine. Of course. Yeah. And as you would expect, we have a full range of grades and geometries to suit these materials. I think it's important that we get the strategy right. And then we think about what grades we should use, because when it comes to, certainly to solid round tools, we have some specific grades for these materials. Yeah. But when it comes to general machining, we have a wide range of different grades that we can use. Okay. Yeah. And I mean, the first ones we look at is, is, is, is when it comes to whether we've got a high heat or low heat in the cutting process. So you can actually start to choose grades based around that strategy. Right. Okay. So if we have an area with, with, with low heat, then we can start to look at the grades like S30T. Okay. Yeah. A PVD grade, really productive. So we've got fine grain carbides. A lot of these are fine grain carbide grades and even micro grain sized carbides. Right. Okay. But with a PVD titanium aluminum nitride coating, we've also got the CVD grades. So we've got the S40T, but we've got the S30T, the PVD, the S40T, the CVD coating and 1130. Right. Yeah. 1130 is, is, is, is one of our newer grades using the Zertivo, uh, PVD coating. So we can actually then start to create hard grades with thin coatings that stay sharp. Mm-hmm. And keeping that sharpness is key when it comes to machining materials like titanium. So they said PVD, CVD. Yeah. What's the difference between the two? Uh, a, a, a PVD coating, a physical vapor deposition. Right. Can, we can create very thin coatings, but very hard coatings. Right. Okay. So they tend to be much tougher when it comes to coming in and able to cut, cutting forces. The CVD, chemical vapor deposition, are much thicker coatings, but you then don't get the same sharpness on the edge line. Right. Okay. Yeah. So if you have a long time in cuts, then yes, you want a CVD because it can withstand the heat better. Right. So with a PVD coating, they don't stand the heat so well, but remember your machine and material that isn't good at transferring heat. So the heat is going to go into the tool. Right. Okay. And that's something we're trying to avoid most of the time. Yeah. So we still need to use PVD grades, but we still need to adjust the cutting strategy to suit the grade we're using. Right. Okay. Yeah. And then of course, we've always got 1010. Mm-hmm. Another grade, which is very hard. It's one of the hardest substrates we have, but again, PVD coated to keep the sharpness. Right. We've still got the stainless grades we can use in these materials and they work very well. You've got the 2040, which is a tough CVD coated grade, and we've also got the 1040. Mm-hmm. Now, when it comes to solid round tools, we've got a specific grade in 1745. Yep. And I'm sure you know as much as I do about these grades when it comes to this type of material. So we're seeing similarities between what you spoke about before about the tough substrate, you know, and that's what we need, you know, for this. Yeah. You know, these products with the 1745, obviously we've talked about the grade developed with a specific grade for that material. But also, you know, we spoke about geometry as well and taking that into account, you know, So with this product, we've got a geometry that's suited for titanium. A lot of work was done. Certainly we spoke about hide feed side milling and looking at the strategies and the effect that that has on the tool and ensuring that we had the correct geometry to match those strategies. Smaller engagement. We can run higher VCs and then we can manage that heat as well from there. With these as well, we've got the coolant booster. So we spoke about the importance of managing the heat. Absolutely. So we've got the coolant booster so we can distribute the coolant all the way up the cutting edge. You know, not only keeping those chips away, certainly if we're looking at pocketing applications, because the last thing we want to do is be re-cutting those chips, but also ensuring that we've got the coolant going in the right place. Because, you know, if we have external coolant, sometimes that can cause us a lot of problems as well. So, yeah, we do have the geometry now to match the grade and to match the strategies that we use within solid round tools milling. A big advantage with the 1745 is it has an extra coating on the outside, which is a silicon coating. Yes. Yeah. So we can actually reduce that chemical reaction. So we're looking at all the different ways that we can improve the process to give a more productive, longer tool life. Yeah. So I think that grade really works well in that area. Yeah, absolutely. So we've looked at titanium machining. So now we're going to have a little look now at the nickel based allies, because I suppose even though they have some characteristics maybe that are similar, they're also very different themselves in the materials. Exactly. They can be. Yes. And as you said, if we look at the nickel based allies, so we're going to move away from titanium, but we're also looking at HRSA now that is used in aircraft engines where they have similar needs. But we've got to remember that when we look at the nickel based alloys, we're looking at high tensile strength materials that need added toughness. Okay. Yeah. So we're looking at something that also needs corrosion resistance and heat resistance. Right. So as we've seen from the earlier slides, we know that HRSAs aren't good at conducting heat. Yeah. So they tend to hold the heat a lot in the cutting area. So we know that the most common of the materials in the nickel based alloys is in Canal 718. Yeah. We're all used to seeing that one around. But by adding nickel to any materials, we're going to increase the tensile strength of the material. Right. That's the main reason we add it. But then when we look at the other alloying components, we add in cobalt, we add in molybdenum, we add in vanadium, and they all add strength as we start to increase the temperature. And you know that we're looking at heat resistant super alloys for the reason that we need to get away to resist heat. Yeah. So any area that needs that property, we need to think about our strategies again. Yeah. Yeah. So we need to think about how we're going to cope with these different areas. We know that the high strength at high cutting temperatures creates high cutting forces. Yeah. We know that the segmented chip formation as with titanium will give this dynamic cyclic cutting forces. Right. So it's going to create problems for us as we're machining. Again, the thermal conductivity is important. The nickel based alloys have poor thermal conductivity, which means we're going to have high temperatures at the cutting edge. So again, we're going to have to start thinking of grades and strategies to reduce temperatures. We know they have high hardness. So this will give also high temperatures. And also this creates another problem. Once you've created a machine surface, you're going to work hard on that surface. Right. So then you're going to have issues with notch wear at depth of cut because we're starting to machine harder surfaces. Yeah. Create more heat, create that instability. We know that the material structure contains hard carbides. And that also gives us another problem. Right. Because then we've got this abrasive load on the insert or the tool edge line, which is then going to start to create more wear and possibly then also create cracked edge lines. Right. Okay. So we've got to be very careful when we start to machine these edges. Okay. So as we can see from this slide, you can see the two different types of chips. And when we're talking of heat resistant super alloys and titaniums, we have this segmented chip. Right. Which is going to vary the loads. So we're going to cut in fours. It's going to vary all the time. The other picture is a laminated chip, which you see in steels, alloyed steels, low alloyed steels. Yeah. And that is much easier to remove. It cuts very easily evenly. We have regular cutting forces. So it's just being aware of the difference in the two chip formations that will create the problems. Of course, we have to be aware of the condition of the material. Now, not all material we machine is going to be in bar. And the material condition is going to affect the way that material cuts. Yeah. So whether you have a cast material, whether you have a forged material, if you have a powder metallic material, they will all react slightly differently. So you might have the same material description, should we say. Yeah. But depending on what form that material comes in can make a difference between the actual machining of it and the materials themselves. Absolutely. And that's something that we have to just be aware of when we're starting to plan our workflow. Okay. And exactly how we're going to program this and how we're going to work with it. Of course, also there's different suppliers. Yep. A material you buy from one supplier may not be the same as a material you buy from another, even though it has the same designation. Right. And like anything that's made, there are tolerances. Yeah. Yeah. The manufacturers work within their tolerances and it could be as much as one or 2% different in the different alloying elements, which could be a huge difference when it comes to machine ability. Right. Okay. So where you get your materials from the condition in, the condition it is in is also important. So we're back to what grades to use. Yeah. So I suppose again, same considerations, different material. Mm-hmm. Are we talking about same grades or would we see differences between what we use for titanium to what we use for the nickel base then? There are differences. Okay. But there are also similarities. Right. Okay. So depending on the application again, we're still talking about controlling heat. We're still talking about cutting forces and reducing the cutting forces. But we're talking about now thin PVD coated inserts. Okay. As our first choice. Right. Yeah. So 1130, the, the, the, once again, the desertivo coated PVD grades are the important grades to start with, with these materials. We can use the S40T. So the tougher materials, if we need added toughness. Right. And then we've got S30T as well. So you've got the similar grades in there, but not in the same order. Right. Yeah. You use them slightly differently. Okay. And of course you've got the, the, the stainless steel grades that also work in this area at low, low cutting speeds where you need toughness. Right. Okay. So you've got a quite a range there of grades that you can use depending on the application, depending on whether you're looking to remove material quickly or whether you need the added toughness. Okay. But then we've also got some other grades, which are more specific to solid round tools. Yep. So we're talking about the 1710 grade that we see, you know, within our range. So, you know, again, this is a kind of material specific grade that we've chosen for this product. Yeah. So if we're talking about 1710, 1745, we spoke to Bob, what's the differences between the two then? They are different coatings. Okay. So, obviously we, we, we're not so much worried now about the chemical reaction with the material. Right. So we don't need the silica coating. Right. But we do need hard, wear resistant coatings. Okay. So again, we've got a very, I would say tough because it's a PVD great, a PVD coated edge line. Mm-hmm. But we've got a hard micro grain carbide with a PVD coating. Right. So we've got a good combination there that works well with these materials. Okay. In combination with the geometry. Yeah, absolutely. And I guess there's a special geometry there. You know, when we developed these products, you know, both with the titanium and the nickel-based alloys, we, we kind of, you know, looked at the information that you've spoken about and saw that we needed differences, not only with the grade, but obviously with the geometry as well. And that's where we see the difference between the products. You know, we see that, uh, we, uh, the geometry required is different. Uh, we have a, uh, specific corner radius designed for, for the nickel-based alloys as well to support that radius that we see on the, on the cutters. It gives us that extra strength that we need, uh, in the cutter itself. So, you know, it gives us a higher stiffness when we look at the core dimensions. If we look to the titanium alloy, uh, cutter, we saw there that we had six flutes. And with this cutter, we've gone to five and that's to give us that rigidity that we need, that stiffness that we need, that stiffness that we need to help machine the nickel-based alloys. So there is differences, not only in the geometry, but also a number of teeth can make a massive difference as well with the cutting process. I guess because we're using, we're machining tougher materials, then it's important that we have a, a geometry that can cope with those cutting forces, those highest cutting forces. Absolutely. Absolutely. Like you said, and as we look at the, you know, we've talked about high feed side milling with these, this is what the, the strategy that we're looking at when it comes to both the, the titanium cuts we spoke about and the nickel-based alloys. And we can see here, you know, with the high feed side milling family, that the largest number of products that we have within this family is within the, the ISO S area, you know, because it's really important to have those small engagements. Uh, but you know, we are able to also have, you know, longer length. So even though our radial engagement might be small, you know, we're going up to five times D with some of our cutters in, in milling applications, certainly within titanium milling. In depth. Yeah. So, you know, we can still have that high metal removal rate. Yeah. And that's replicated, you know, across the, the different material groups as well. So we can apply these different strategies, you know, to, to the other materials within that group. Yeah. Okay. So when you're talking about the strategies, you're talking about the, the, the depth of cut AP against the AE. Yeah, absolutely. So if we're looking at, you know, uh, engagement, we want to have a small, uh, radial engagement, keep that, uh, engagement as small as possible helps to manage the heat. Yeah. As well as keeping, you know, a smooth tool path as well. It's really important. It's something we spoke about in the other knowledge sessions, certainly when we've looked at the pocketing strategies, you know, making smooth, we've got a smooth tool path for those tools to follow because any, you know, uh, sharp movements, any, you know, digs into the material or anything like that is going to cause us problems. Certainly in the ISS area, you know, like we've spoken about, we want to try and have as much uniform cutting action as possible because there's so many variables that can affect, uh, the machining strategy. And we know that when, when you look at the application and you look at the high heat developed during this process, you end up with inconsistent chips, inconsistent chip thicknesses for certain, but you get low material removal rates because you're, you're trying to manage the heat. Absolutely. But if you could actually sort of stick to the cutting processes and use the cutting strategies. So the applications with the high AP and the low AE, then you can actually then improve the cutting process. Yeah, absolutely. And because you're taking these into account, it doesn't mean that we have to run slow. You know, we can run some of the titanium cutters at 150 meters a minute. And that's because, you know, we're taking into consideration all the different factors, making sure we've got this smooth toolpath, small engagement. So even though we may be going to small engagement, we may actually have a more productive process in place because then we can start to push the VC. We can get that feed up because we don't want to be rubbing on the tool and causing us more heat generation, more issues there. So, yeah, it's really important when we look at this to kind of, you know, make sure we're applying the strategy as a whole in the correct way. So we're using that low engagement so that we can actually improve stability. Yeah, absolutely. That's the main part for it. But as you said, higher feed rates. Yeah, without a doubt. And of course, then we've also got the optimized toolpaths. Yeah, optimized toolpath. You know, we spoke about climb milling. You know, we're looking at rolling into cut, you know, keeping those engagements constant all the time, you know, to help give us a really good process. And this is all about reducing heat and reducing the cutting process. Yeah. I mean, the heat's the main issue. I think we'd agree when we're looking at these kind of materials and it's managing that heat wherever we possibly can. Yeah. So as we can see, everything there relates to a stable, reliable process. Absolutely. And that's the key thing that we're aiming for when we talk about machining these types of materials. So really then in summary of what we've talked about today, we've talked about the HRSA materials and how they have poor thermal conductivity. Mm-hmm. This leads to massive heat generation, especially in the cutting area. And that's the main thing that we're trying to avoid. We know these temperatures could get very high and we're talking 1,100 degrees at the cutting point. So we know that this could cause a lot of problems. We know that work hardening the machine surface will cause us notch wear, certainly a depth of cut, but we've got hard particles in there. So we're creating a hard surface and we're actually increasing the abrasive wear on the tool. We know that the cutting tool material will conduct the heat better than the work piece material. Yeah. So the cutting tool is going to get hot. So we're not going to see the heat disappearing in the chips as we would normally with cutting steel. We're going to see the heat actually building up in the cutting tool, which is going to create even more problems. So we need to balance the heat generation. Mm-hmm. And it's the processes that we've talked about earlier that actually create this. And that's the biggest factor, you know, the heat generation and managing that heat, you know, with both materials, with titanium and the nickel-based alloys. You know, heat is the enemy, shall we say. And that's what's going to cause the biggest amount of problems with this kind of machining. Yeah. And we also know that during intermittent machining operations, the temperature at the cutting edge will vary all the time. So not just the temperature, but also the forces on the cutting edge. And that's again something that we have to balance that we've talked about earlier. So we know the cutting temperatures are always going to be a problem. We know there's always a risk of thermal cracks. So when we look at the wear patterns, we know it's going to be notch wear, it's going to be thermal cracks, and it's going to be edge line chipping. And they're the three things that we need to think about when we think about our cutting processes for these materials. So to avoid the tool wear problems such as thermal cracks and notch and chipping, we need to look at the application, the way we actually apply these tools. Look at the tool paths as you've spoken about. Yeah. Yeah. That's the best way forward with that. So we need to avoid vibrations by ensuring that we have the minimum tool overhangs. We have stable machines. We have machine units that are capable of the speeds and changing in direction. So getting stability right at the start is a key factor. Yeah. And then we start to think about the grades as we talked about earlier, grades and geometries. So we've covered a lot today. I think that's really good that we've previously looked at strategies when it comes to milling operations. Certainly when we looked at slotting, we've looked at pocketing and had specific sessions on that. So, you know, if people are wanting to look back at them, then they are able to see actually how we apply the tools in more detail. But here, I think we've done really a good session where we've covered the material characteristics and what issues that that can have. So, you know, thank you very much for joining us today, Martin. It's much appreciated. It is no problem. And I said the key with this is understand the material. If you understand the material, then you could very quickly decide a strategy to machine that material. Great. That's the key. Great. Thank you. Thank you. If you'd like more information on the topics that we've covered today, then please follow the link on the screen or the QR code. Thank you.